One-face resistance welding machine



June 23, 1936. P. w. FASSLER ONE-FACE RESISTANCE WELDING CHINE Filed April 15, 1935 3 Sheets-Sheet l TINVENTOR flzzvwfi z BY ATTORNEY.

June 23, 1936. v P. w. FASSLER 2,045,523:

[HUS-FACE BESISTANCE WELDING MACHINE I Filed Ap;'il 15, 1935 3 sheets-sheet 3 I76 1 #2 I I w 176- I I l I I l 15 I ,Afl I f I 177 [j] INVENT OR.

' Wafer wafer W AO Patented June 23, 1936 u I UNITED STATES PATENT OFFICE Peter W. Fassler; Detroit, Mich. Application April 15, 1935, Serial No. 16,320

Claims. (Cl. 219-4) This invention relates to welding machines pressure to one side of work to be welded, the and in particular to resistance welding machines said electrodes being so mounted to cause only a which operate on one face of the work welded minimum reactance to the entire welding cirthereby. cult of the said machine. I

5 In the conventional spot or seam welding ma Another object of this invention is to provide 5 chines which are mostly built to perform a 'plua resistance spot welding machine in which one rality of welds with the electrodes thereof in elecelectrode is circumscribed or surrounded by t e trical parallel relationship, the work is laid beother and both electrodes ada'pted to be applied tween the electrodes and welded under pressure. under pressure to o e Side o the Wor being In the conventional resistance series welding ma- Welded thereby, and in which both electrodes are 10 chine, two or more electrodes are applied to one Slidably mounted through tlranfifol'mer, the side of th work t b welded therein i t isaid relation of electrodes, transformer and work cal series relationship and a contact bridge of being welded a in a minimum reactance in high electric conductivity is applied to the other t e en e secondary circuit of the said weldin side of the work as a current carrier, the said machine- 15 bridgeeXerting-pressure on the work during weld- Qthe! j s f t s inv nt n will ome Bil?- ing. In the present invention, both electrodes parent b reference to h llow n d tail d dcare applied to one id of th work t um ie t scription taken in connection with the followpressure to permit the welding current to pass ing drawings, in which:

-10 through the 'work to be welded together without 1 is a View Part in section and P in arcing therebetween, the said electrodes being in elevation Showing a Welding Ina-chine embodying such a relation to each other as to effectively perthe inventioni form a single resistance t 1 Fig. 2 is a view-part in section and partin ele- One object of this invention is to provide a one Vation illustrating another embodiment of h face resistance welding machine. invenhon- 25 Another object or this invention is to provide 318 a part top view illustrating a p rtabl a resistance spot welding machine in which one welding machine embodying the inventionelectrode is circumscribed by the other and both Fig. 4 is a view part in section and part in electrodes are applied with pressure to one side of elevation taken substantially oh the hhe of the work to be welded thereby. Fig. 3. 30

Another obj ect of t invention is to Fig. 5 is a section taken on the line 5-5 of Fig. 4 vide a machine for performing a resistance weld looking in the direction indicated by the arrowsentirely from one side of the work to be welded, Referring HOW to the w ngs and particularsaid resistance weld being in the nature of a 1y to the embodiment shown in the Weld spot weld accomplished under pressure by elecihg ,compflses in general a base 35 trodes in electrical series relationship, one of ihg a transformer H secured thereon but said electrodes being preferably circumscribed or lated therefrom by any suitable insulation surrounded by the th erally designated by the numeral l2. An operat- Another object of this invention is to provide ing head is cantilevered fQIWaI'd from the 40 a machine for making a one face resistance spot top of the Said transformer H insulated 40 weld in which both electrodes thereof are applied therefrom by insulation under pressure to one face of work to be welded The transformer ll illustrated herein having using where necessary and when required a supbeen disclosed and claimed inmy patent for Weldport or the like to back up said k ing transformers, Patent No. 1,986,884, is not a Another object f this invention i t prpvide part of this invention, however, its use is preferone face resistance spot welding machine fo able to transformers of the usual type and is welding box shaped structures and the like, the hi h desirable w a rm r h vin a said machine and electrodes being so arranged as multiple tum Secondary Winding is qu ed to encompass a minimum amount of work and becomes advantageous. The transformer H conspace, thereby reducing the reactance of th sists in general of a combined housing and secon- 50 tire welding circuit of the said machine. dary winding I4, and a core l5 and primary wind- Another object of this invention is to provide ing '5 Within he Sa h ll I a resistant. spot welding machine in which one A preferably cylindrical electrode carrier I1 is electrode is reciprocally mounted within the other id ly mount with n a v rt lly disposed and both electrodes are adapted to be applied with annular sleeve ill at the outer end of the operatl ing head i3 but insulated therefrom by any suitable insulation I2. An adjustable work support I8 is located directly below the annular sleeve I8 in vertically spaced relation thereta. The work support I8 is secured to the upper end of a screw 28 which is turnable within a threaded sleeve 2| at the outer end of a bracket 22 secured to' the transformer I I by insulated bolts 23 and insulated therefrom by any suitable insulation I2. The work support I9 may be maintained in any desired vertical adjustment by turning a lock nut 24 on the screw 28 against the upper face of the threaded sleeve 2I by means of radially disposed hand grips 25.

The cylindrical electrode carrier I1 is provided with an axially disposed annular bore 26 extending from the bottom thereof upward to a point sufllciently high to accommodate a tubular electrode 21 having a solid electrode holder 23 slidably mounted therein with a space left between the upper end of the solid electrode holder 28 and the upper end of the bore 28. One side of the said electrode carrier I1 is provided with an arcuate radially extending collar 28 which depends below the normal bottom of the said electrode carrier Ill. The said depending collar .29 is provfded with an inwardly disposed notch 38 forming upper and lower shoulders 3i and 32which cooperate with a radially extending lug 33 on the tubular electrode 21 to move and limit the movement of the said tubular electrode as hereinafter described.

Aspring 34 at the upper end of the annular bore 28 of the electrode carrier I1 urges the tubular electrode 21 downward to its normal position with its lug 33 against the lower shoulder 32 of the depending collar 28.

The tubular electrode 21 has a spring chamber 85 formed therein to accommodate a spring 38 which normally urges the solid electrode holder 28 to its normal upward position as shown in the drawings by acting against a radially extending annular lug 81 on the electrode holder '28 and the lower shoulder 38 formed by thespring chamber 35. The said lug 31 bearing against the upper shoulder 39 formed by the spring chamber limits the upward movement of the solid electrode holder 28 in relation to the tubular electrode 21. A centrally disposed electrode 48 may be wedged or otherwise secured in the lower end of the solid electrode holder 28.

The cylindrical electrode carrier I1 is provided with a lug 4| to which a flexible lead 42 supplies welding current from one secondary transformer terminal, and the tubular electrode 21 is provided with a similar lug 48 to which a flexible lead 44 supplies welding current from the other secondary transformer terminal.

It will be noted that the cylindrical electrode carrier I1, the tubular electrode 21 and the solid electrode holder 28. are each insulated from each other by any suitable insulation generally designated by the numeral I2, however, the top oi! the solid electrodeholder 28 is uninsulated inasmuch as it receives weldingcurrent through contact with the cylindrical electrode carrier I 1 at the top of the annular bore 26 which is designated by numeral 45' in Fig. 1 oithe drawings.

The cylindrical electrode carrier I1 is held in its normal upward position by suspension from a bifurcated end of an overhead lever 48 by means oi two links 41 connected to the said electrodet 1 carrier with a pin 48 and journaled to the overhead 'lever 48 by the pins v49 hushed with any suitable insulation I2.

"83 of the sliding joint84 oi the jointed linkage The said overhead lever 48 be hingedly supported from the operating head I8 by means oi? a U-shaped bracket 58 and the hinge pin 5I. A vertical jointed linkage member 52 having a spring seat 53 formed thereon is hingedly connected to the rear of the overhead lever 48 and to the rear 01 a lower lever 54 by pins 55 and 56 respectively. The said lower lever 54 is mounted on a shaft 51 journaled in the base I8 of the machine and extends through slots 58 and 59 in the front and rear of .the base I8 respectively. A suitable pedal 68 is provided on the forward end of the lower lever 54.

An angle 8| is secured to the rear of the transformer I I but insulated therefrom and situated in such'a relation to the spring seat 53 on the linkage member 52 that a suitable spring 62 around the linkage member 52 between the angle SI and the spring seat 53 will constantly urge the said linkage member downward toefnormal position holding the rearward portion of fine lower lever 54 to its lower limit against the rear wall of the base I8 at the bottom ofthe slot 58, in which position through the system of linkage hereinbefore described, the cylindrical electrode carrier I1 and the operating pedal 68 are maintained in a nor- 25 mal position ready for operation.

In operating the embodiment of this invention shown in Fig. 1, the work support I9 is adjusted to the required level and the work W is placed thereon positioned under the electrode 48 for 30 welding. The operator. depresses the foot pedal 88 which first causes the cylindrical electrode carrier I1 to slide downwardly carrying the tubular electrode 21 into contact withthe work W; additional downward movement of the electrode carrier I1 then causes the tubular electrode 21 to telescope within the cylindrical electrode carrier I1 and compress the spring 34 until the top of the solid electrode holder 28 contacts the top of the bore 28 at 45, at which time, the solid electrode holder 28 is carried downwardly with the cylindrical electrode carrier I1, the said electrode holder 28 and the said cylindrical electrode carrier I1 both moving in inner and outer telescopic relationship respectively to the tubular electrade 21.

The last mentioned movement compresses the spring 38 until the centrally disposed electrode 48 contacts the work W. Additional downward pressure on the foot pedal 68 then causes the spring member 52 to compress thereby permitting the lower portion of the jointed linkage member 52 to move upward until suflicient welding pressure has been applied to the work W by both electrodes 21 and 48, atwhich time, the contact-arm 85 on the linkage member 52 closes the circuit in the contactor 88 which actuates the adjustable time limit relay 81 causing a flow of alternating current into the transformer primary I8 from a source of alternating current supply designated by thenuinerals 88 and 88 in the drawings. The adjustable time limit relay 81 operating in con-junction with the contactor 88 may be used to regulate the welding time in accordance with the thickness 01 the 05 work W. In the embodiment shown in Fig. 2, the welding machine comprises in general a combined base and upright I88 having a transformer I8I supported on a bracket I82 and secured to the i'or- 70 ward portion of the said upright by any desirable means but insulated therefrom by any suitable insulation generally designated by the numeral I88.

The transformer I8I illustrated in Fig. 2 is bined housing and secondary winding I06. Lugs I01 and I08 on the secondary winding serve as the secondary terminals of the transformer.

An adjustable work support I09 is centered under the center of the transformer and located in vertically spaced relation thereto. The work support I09 is secured to the upper end of a screw I I which is turnable within a threaded sleeve I I I fastened by suitable means to the base I00 but insulated therefrom by any suitable insulation I03. The work support I09 may be maintained in any desired vertical adjustment by turning a lock nut I I2 against the upper'face of the threaded sleeve II I by means of radially disposed hand grips II 3.

The transformer housing I06 is formed to provide upper and lower central inwardly disposed annular sleeves H4 and H5 respectively. A vertically disposed tubular electrode H6 is slidably mounted through the lower annular sleeve H5 and is connected to the transformer terminal I08 by the flexible lead II1. A solid electrode holder H8 is slidably mounted through the upper annular sleeve H4 and extends downward through the center of the transformer IOI to and within the tubular electrode H6 in telescopic relation thereto. A flexible lead II9 connects the solid electrode holder IIB to the transformer terminal I01.

The tubular electrode I I6 has a spring chamber I formed therein to accommodate a spring I2I which normally urges the said tubular electrode I I 6 to the normal position shown in the drawings by acting against a radially extending annular lug I22 on the solid electrode holder H8 and a lower shoulder I23 formed by the spring chamber I20. The said lug I22 bearing against an upper shoulder I24 formed by the spring chamber I20 limits the downward movement of the tubular electrode H6 in relation to the solid electrode holder II8. A centrally disposed electrode I25 may be wedged or otherwise secured in the lower end of the solid electrode'holder I I 8.

It will be noted that the tubular electrode. H6 is insulated from the solid electrode holder H8 and that both the tubular electrode H6 and the solid electrode holder II8 are insulated from the annular sleeves H5 and H4 respectively of the combined housing and secondary winding I05 of the transformer I ,0I by any suitable insulation generally designated by the numeral I03.

The solid electrode holder I I3 which carries the tubular electrode I I6 is held in its normal upward position by suspension from the bifurcated forward end of an overhead lever I26 by means of two links I21 connected to the said electrode holder II8 with a pin I28 and journaled to the overhead lever I26 by the pins I29 bushed with any suitable insulation I03.

The said overhead lever I26 may be hingedly supported from the top of the combined base and upright I00 by means of a U-shaped bracket I30 and the hinge pin I 3|. A vertical jointed linkage member I32 having a spring seat I33 formed thereon is hingedly connected to the rear of the overhead lever I26 and to the rear of the lower lever I34 by pins I35 and I36 respectively. The said lower lever I34 is mounted on'a shaft I31 journaled in the base I 00 of the welding machine and extends through the slot I38 in the front of the said base I00. A suitable foot pedal I39 is provided at the forward end of the lower lever I34.

A bracket I40 is suitably located in relation to the spring seat I33 on the linkage member I32 to permit a spring I4I around the linkage member I32 between the bracket I40 and the spring seat I33 to constantly urge the said linkage member I32downward to a normal position holding the forward portion of the lower lever I34 to its upward limit against the front wall of the base I00 at the top of the slot IBfi, in which position through the system of linkage hereinbefore described, the solid electrode hblder H8 and the operating foot pedal I39 are maintained in a normal position ready for operation.

In operating the embodiment of this invention shown in Fig. 2, the work support I09 is adjusted to'the required level and the work W is placed thereon positioned under the electrode I25 for ,welding. The operator depresses the foot pedal I39 which first causes the solid electrode holder I I8 to slide downwardly carrying the tubular electrode IIB into contact with the work W; additional downward movement of the solid electrode holder I I8 then causes it to telescope within the tubular electrode H6 and compress the spring I2I until the centrally disposed elect-rode I25 contacts the work W.

Additional downward pressure on the footpedal I39 then causes the spring I42 of the sliding joint I43 to compress thereby permitting the lower portion of the jointed linkage member I32 to move upward until sufiicient welding pressure has been applied to the work W by both electrodes I I6 and I25, at which time the contact arm I44 on the linkage member I32 closes the circuit in the contactor I45 which actuates an adjustable time limit relay I46 causing a flow of alternating current into the transformer primary I05 from a source of alternating current supply designated by the numerals I41 and I48 in the drawings. The adjustable time limit relay I46 operating in conjunction with thecontactor I45 may be used to regulate the welding time in accordance with the thickness of the work VI.

Figs. 3, 4 and 5 illustrate a portable welding machine embodying this invention which comprises a combined tubular electrode and hexagonal housing I50 having a solid electrode holder.

I5I slidably mounted therein. A centrally disposed electrode I52 may be wedged or otherwise secured in the lower end of the solid electrode holder I5I.

Fig. 4 shows both the tubular electrode I50 and the centrally disposed electrode I52 in operating contact with the work W in which position the electrodes are maintained under welding pressure by its operator urging the machine against the work W by means of a hand grip I53 and an operating lever I54. 7

The tubular electrode I50-. having the radially disposed hand grip I53 mounted on one side F thereof is bored to provide an inwardly disposed annular lug I55 forming a shoulder I56 against which a spring I51 within the said tubular electrode I50 acts and normally urges the solid electrode holder I5I upward by exerting pressure againstan annular shoulder I58 of the solid elecplug I6I mounted therein which is normally urged to its upward position illustrated by the dotted lines I62 by means of a spring I63. The

top of the plug I6l is'insulated from its shank V by any suitable insulation I59. The bottom of the plug I6! is formed into an annular shouldered cup I64, the upper shoulders of which limit the upward movement of the plug IN by acting against the annular radially disposed shoulder I65 just below the tOPwQf the solid electrode holder II.

A pair of brackets I66 preferably integral with the combined tubular electrode and hexagonal housing I50 located directly above the hand grip I53 and in spaced relation to each other provide an anchorage for hingedly mounting the operating lever I54 by means of thehinge-pin I61. The operating lever I54 extends through apertures I 60 an I69 in the upper portion of the hexagonal housing to a, position on the opposite side of the welding machine from the hand grip I53 which will admit of ease in manual operation thereof. The spring I51 in urging the solid electrode holder I5I to its normal 'upward position as hereinbefore described'causes the top of the plug I6I mounted in the top of the solid electrode holder I5I to act against the arcuate portion I10 of the operating lever I54 and maintain it in its normal position indicated by the dotted lines I1I against the hexagonal housing at the top of the aperture I69 therein. One secondary lead I12 of a suitable trans former I13 is connected to a tongue I14 suitably wedged or otherwise secured in the solid electrode holder -I5I, the said tongue protruding through a slotted aperture A15 in the combined tubular electrode and hexagonal housing I 'in' spaced relation thereto. The other secondary lead I16 is connected to a tongue I11 suitably secured to the outside of the combined tubular electrode and hexagonal housing I50. The connection of the secondary leads I12 and I16 of the transformer I13 to the solid electrode holder and the hexagonal housing respectively is best shown in Figs. 3 and 5 of the drawings.

In operating the embodiment of this invention shown in Figs. 3, 4 and 5, the portable welding machine is centered against the work W with its solid electrode holder I5I in its normal position telescoped upwardly within the tubular electrode and hexagonal housing I50 and with the operating lever I54 urged to its upward position indicated by the dotted lines I1I. The work W may be backed up by a support or the like when the nature of the work is such that it will not resist the pressure to be applied thereto during welding without harmful distortion or deflection.

When properly located against the work W, manual pressure is applied equally to the hand grip I 53 and the operating lever I54 toward the workW which maintains the tubular electrode I50 against the said work W and at the same time compresses the spring I51 which permits the solid electrode holder I5I' to move in telescopic relation" to the tubular electrode I50 and bring the centrally disposed electrode I52 in contact with the work W.

Additional manual pressure applied to the hand grip I5; and the operating lever I54 toward the work W then causes the spring I53 in the top of the solid electrode holder I 5| to compress thereby permitting the plug I 6I to move downward until sufiicient welding pressure has been applied to the work W byboth electrodes I50 and I52, at which time the operating lever I54 has reached the downward position shown in Fig. 4 causing the link I18 connected to the operating lever I54 toclose the circuit in the contactor I19 mounted in a suitable housing on top of the combined tubular electrode and hex.- agonal housing I50. The circuit closed by the contactor I 19 actuates a relay I80 which causes a flow of alternating current through the primary winding of the transformer I13 from a source of alternating current supply designated by the numerals I8I and'I82 inFig. 4, The relay I 80 is preferably of the adjustable time limit type having an automatic re-set and may be used to regulate the welding time in accordance with the thickness of the work W.

By referring to Fig. 4, the dotted lines I83 represent the flow of welding current through It will be notedthe work W during welding. that the welding current is highly intensified at central or spot electrode I52 because of the fact thatv the area of the tubular or annular electrode I50 in contact with the work W is many times greater than the area of the central electrode I52 in contact withthe work W. Inasmuch as the contact surface of the electrode I50 is-annular'and all portions thereof are uniformly and radially equidistant from the contact surface of the central electrode I52 and because of the aforementioned difference in area between the contact surfaces of the said electrodes, a substantially perfect resistance type spot weld I84 is accomplished concentric with the central electrode I52. The flow of current through work W in the embodiments shown in Fig. 1 andFig. 2

and the welds accomplished thereby are substantially the same as the flow of current through the work W and the weld accomplished by the embodiment shown in Figs. 3, 4 and 5 herein described. Although it is highly desirable, it is not necessary to have one electrode circumscribed by the other since elliptical, square, triangular or rectangular electrodes may be used providing one electrodelis maintained substantially central or symmetrical to the other and the relative areas, 7

of the electrodes are such as will provide highly intensified welding current at one electrode. It is essential that one electrode be of the spot type as indicated by the central electrode of Figs. 1, 2 and 4.

Any known means for cooling the electrodes of the welding machines herein disclosed is contemplated as may be required, the said cooling means has not "been shown or described inasmuch as -a number of cooling systems already known may be readily applied to welding machines embodying this invention by anyone skilled in the art.

Although but several specific embodiments of this invention have been shown and described herein, it will be understood that various changes including size,shape, arrangement and detail of parts may be made without departing from the spirit of my invention and it is not my intention to limit its scope other than by the terms of the appendedclaima.

- lated therefrom, a tubular electrode telescopingly mounted within said electrode carrier but insulated therefrom, a solid electrode holder telescopingly mounted within said tubular electrode but insulated therefrom, the top of said solid electrode holder uninsuiated from and normally in spaced relation tothe aforementioned electrode carrier, an electrode mounted in said electrode holder and depending therefrom, means for positioning said electrodes in welding relationship to one side of work to be welded thereby, I

said electrode carrier and tubular electrode being connected to the transformer secondary, and means for causing welding current to flow through said electrodes and work.

2. In an electric resistance welding machine, a transformer having a secondary winding which forms a housing therefor, a tubular electrode slidably mounted through one end of said transformer housing but insulated/therefrom, a solid electrode holder telescopingly mounted through said tubular electrode and slidably mounted through the other end of said transformer housing but insulated from both the tubular electrode and the transformer housing, an electrode mounted in said solid electrode holder and de-' pending therefrom, said tubular electrode and solid electrode holder each electrically connected to a secondary transformer terminal, means for positioning said electrodes in welding relationship to one side of work to be welded thereby, and means for causing welding current to flow through said electrodes and work.

3. In'an electric resistance welding machine, a transformer having a secondary winding which forms a housing therefor,-a tubularelectrode, a solid electrode holder telescop'ingly mounted through said tubular electrode but insulated therefrom, an electrode mounted in said solid electrode holder and depending therefrom, both the said tubular electrode and said solid electrode holder being slidably mounted through the transformer housing but insulated therefrom, the tubular electrode connected toone transformer terminal, the solid electrode holder connected to the other transformer terminal, the said electrodes adapted to be urged into welding pressure against one side of work to'be welded thereby, and means for causing welding current to flow through said electrodes andwork.

4. An electric resistance welding machine comprising a transformer having a secondary winding which forms a housing therefo'r, a'tubular electrode, a solid electrode holder teiescopingly mounted in said tubular electro'de'but insulated therefrom, said tubular electrode and solid electrode holder slidably mounted through said transformer secondary but insulated therefrom, said tubular electrode connected to one secondary transformer terminal, said solid-electrode holder connectedto the other secondary transformer terminal, an electrode mounted in said solid electrode holder having an area of contact with work to be welded infinitely less than the araof contact of said tubular electrode, means for positioning said tubular electrode against one side of work to be welded together, means for moving.

the other electrode into "contact with said work and means for causing a flow of welding current through said work after sufficient welding pressure has been applied thereto.

5. In an electric resistance welding machine, in combination, a. spot type central electrode, a tubular electrode having an area of contact infinitely greater than that of said spot type central electrode, said central electrode telescopingly mounted in insulated relation concentric to and within the tubular electrode, means for first bringing and maintaining said tubular electrode in contact with one facelof work to lie-welded together under a desired welding pressure, means for then bringing and maintaining said spot type electrode in contact with thesame face of work to be welded together under a desired welding pressure, and automatic means responsive to said last mentioned pressure means for, causing a flow of welding current through said electrodes and work when sufficient welding pressure has been applied thereto.

' PETER W. FASSLER. 

